What a sad situation for the OP.
I think that if you want to carry on this relationship with him, and if you are happy with the non sex side of the relationship, then i'd shove an unlimatium his way that he seeks, activly seeks that is, medical attention about these issues and problems.
The more i read of this the more it makes me suspect that he has got some long seated hangups and problems with sex and womens bodies.
There could be many causes for that it may also be that he is suffering from some drug side effect and or effects that may not be his fault as such BUT it is up to him to see if it can be put right. Thats mainly the inability to ejaculate inside the vagina.
Eeven so i think that this issue goes even deeper than that, the overal "sex" thing seems not as it ough be with him. I beliven the OP said that he had this or similar problems with other partners?
A few other observations FWTW.
Over many years of sexual encounters with women and the odd one or two with men, I've had my fair share and more;) that said;
I've yet to meet a woman who did not like Oral sex.
Most woman don't pop from PIV sex alone though there is a slight variant of the missionray position that makes it a bit more possible.
Simply said, some women find it easier than others to orgasm anyway some have never had, some are very easy to make pop, some need extened forplay mouth fingers etc. AND they need to feel in the right mood and feel its what they want to do either excited or suitably relaxed whatever suites them best.
Some readers, inc our man in question, ought read up on IVF espically relating to this instance. Of course lesbian couples have mamaged fine with a "donation" and a 10 quid turkey baster! Thast in itself if there was an insumountale problem would be justified but if all other avenues of enquiry had been exhausted.
And i wouln't consider pornhub etc a decent source of sex techinique and edcuation most all porn vids are exageration's of what normally happens between lovers and or partners, they are shot from angles that are not that normal in order for the viewers to get a good "gawp" at the action.
They'd be far better off learning as i did with a few encounters whilst younger with more expeicned older women who shall we say "knew what they liked and wanted" and put my fumblings right and I thank them for that!.
Finally it may be mansplning but i think its a mans duty to sasify his woman:)
Mind you its a selfish thing as if shes happy then i'm happy too:)